1. Field of the Invention
The present invention relates to an endoscopic system for position control of surgical instruments such as a scalpel and a forceps to be inserted through a forceps channel of an endoscopic apparatus.
2. Description of the Related Art
An endoscopic apparatus is generally known as equipment for observing, for example, a lesion in a body cavity. This endoscopic apparatus has an imaging unit which is provided at the distal portion of an insertion portion of an endoscope to be inserted into the body cavity or which is provided in the main unit of the apparatus. Thus, the endoscopic apparatus displays a desired observation target as an image on a monitor. This insertion portion is flexible, and is provided with a channel (forceps channel) penetrating from the proximal side to the distal end. A surgical instrument such as a pair of forceps or a scalpel (electric scalpel) is inserted as needed from an insertion hole of the forceps channel, so that various treatments can be administered to, for example, the lesion while endoscopic images are being observed at the same time.
Furthermore, as disclosed in, for example, Japanese Patent No. 3007715, there has recently been proposed an electrically operated endoscopic apparatus to reduce the burden on a surgeon in the operation of an endoscope. Moreover, in connection with a surgical instrument, as disclosed in, for example, Jpn. Pat. Appln. KOKAI Publication No. 2003-127076, there has been proposed an electrically operated and robotized surgical instrument not only to reduce the operational burden on the surgeon but also to reduce the burden on a patient by the reduction of the time for an operation.
In a surgery using an endoscope, a biomedical tissue (affected area) in which, for example, a lesion is generated is cut and detached by a surgical instrument inserted through a forceps channel of the endoscope. Here, the affected area is detached so that a view between a mucous membrane and a muscular coat may be secured by lifting, with a holding pair of forceps, the mucous membrane cut by a scalpel. In this case, as the held mucous membrane becomes greater along with the progress of detachment, motion in the direction of gravity or motion opposite to the direction of the lifting with the holding pair of forceps acts on the endoscope due to the increase of the weight of the mucous membrane or the increase in the amount of lifting with the holding pair of forceps. If this motion is great, the distal end of the scalpel also moves away from the position of the treatment, so that a surgeon performs the operation of returning the distal end of the scalpel to the original treatment position every time. Further, for example, Japanese Patent No. 3236070 discloses a technique for moving an endoscope in accordance with the movement of the distal end of a surgical instrument.